1. Field of the Invention
This invention relates generally to the measurement of gas phase entrained in process streams comprised of a liquid phase or a liquid phase containing suspended solid material.
2. Description of the Prior Art
Some of the prior art used for laboratory measurements of entrained air in process streams utilizes direct measurement by expansibility of isolated process stream samples subjected to reduced pressure. See, for example:
J. D. Boadway, "Gas in Papermaking Stock," Pulp and Paper Magazine of Canada, Convention Issue, Vol. 57, No. 3, 1956, pp. 185-189, 194. PA1 E. Parker Troland, "Measuring Suspended Air in Paper Stock," Tappi, Vol. 49, No. 9, September 1966, pp. 100A-102A. PA1 P. Landmark, "New Apparatus for Determining Entrained Air in Pulp Suspensions," Norsk Skogind., Vol. 21, No. 12, December 1967, pp. 503-506. PA1 E. Barkowski, "Air in Aqueous Stock Suspension-Methods for Determining Air Content," Papiermacher, Vol. 28, No. 3, Mar. 18, 1978, pp. 44-46.
All of these methods provide a direct measurement of the entrained air content by means of collection and isolation of a sample, subjection of the sample to reduced pressure, measurement of the expansion of the sample due to the expansion of the entrained gas phase, and, by means of common thermodynamic equations of state, calculation of the fraction of sample which is entrained gas phase.
An important observation about the prior art is that in neither these references, nor in any of the open literature, is mention made of compressing rather than expanding an isolated sample in order to measure its entrained gas-phase content. In addition, none of the apparatus disclosed in the prior art is capable of compressing an isolated sample. Furthermore, none of the prior art is capable of providing on-line automatic process measurements due to a number of factors, including for example, fragile construction, pluggage with particulate material, and leakage of sealing valves.
The present invention describes the determination of the entrained gas-phase content of process streams by means of the compression of process samples, and also describes an apparatus which automatically provides direct and on-line entrained gas-phase measurement using compression of process samples rather than expansion of process samples.